KENNEDY SPACE CENTER, Fla. — Launch Complex 39A began its third career after serving as the site for historic Apollo and Space Shuttle launches. Today it welcomed its first commercial launch, with SpaceX sending Cargo Resupply Service (CRS) 10 aboard the Dragon spacecraft perched atop the ‘Full Thrust’ Falcon 9.

Liftoff took place on a cloudy and somewhat rainy morning at 9:39 a.m. EST (14:39 GMT) Feb. 19, 2017. After providing a brief, fiery glimpse, the rocket disappeared behind a dense layer of clouds. However, the two-stage rocket refused to be ignored. The dense layer of clouds caused the thunderous noise of its nine Merlin 1D engines, arranged in the “Octa-Web” formation to powerfully resonate. SpaceFlight Insider staff, atop the CBS News building, reported that they felt the structure shudder under the might unleashed by the NewSpace booster.

This was the second launch attempt, however. On Saturday, Feb. 19, the SpaceX team was working a couple of issues during an otherwise smooth countdown. The issue that ultimately resulted in the scrub of the attempt was an “out of family” reading on the second stage thrust vector control system.

“While [the Feb. 18] scrub with just 13 seconds to go is an obvious disappointment, space flight is hard and these events are not unexpected,” Dan Batcheldor, interim department head of the Physics and Space Sciences department at Florida Institute of Technology told SpaceFlight Insider. “It is much better to scrub a launch than to lose an entire mission.”

Batcheldor said he was grateful, however, to have had the experience of sharing the Feb. 18 launch attempt with space legends such as Buzz Aldrin, Al Worden, Bob Cabana and John Grunsfeld.

While the weather did not end up being a concern during the first launch attempt, for the second launch attempt, it was raining until about 45 minutes before liftoff. The cumulus cloud constraint remained no-go until about 25 minutes before launch.

The soggy weather was reminiscent of the final Space Shuttle launch in July of 2011. For that flight, however, the weather was expected to only provide a 30 percent chance of favorable conditions, while the CRS-10 mission had a 70 percent chance. In both cases, however, the weather cleared when it was most important.

Fire and smoke return to LC-39A

SpaceX’s launches for LC-39A follow the same procedures that they follow for Space Launch Complex (SLC) 40. The major difference is the configuration of the pad itself, as LC-39A is built on a large reinforced concrete beam with a 42.6-foot (13-meter) deep flame trench to direct the powerful forces incurred during liftoff.

Fueling for the Falcon 9 began at approximately T-minus 70 minutes before launch for RP-1 (a highly refined version of kerosene) while the liquid oxygen began loading at about T-minus 45 minutes. The engines were chilled down for launch at T-minus 7 minutes.

While LC-39A already had tanks for storing liquid oxygen, SpaceX had to add tanks for RP-1 (kerosene) and their related plumbing.

The last mission to launch from LC-39A was STS-135 flown by Space Shuttle Atlantis on July 8, 2011. Photo Credit: Charles Twine / SpaceFlight Insider

As is always the case with launches to the International Space Station, CRS-10 was on a tight schedule to be in the right place to catch up with the ISS. This is what is referred to as an “instantaneous” (one second) launch window. At T-minus zero, the nine Merlin engines crackled to life with orange flame and sent the rocket skyward.

After clearing the tower, the vehicle executed a pitch and roll maneuver to turn in the direction of the 51.6-degree azimuth to match the space station’s orbit, which took it over Russia.

Two minutes into the flight the Falcon 9’s first stage separated and began its controlled return to Earth at T-plus 2 minutes, 41 seconds. Following the stage’s entry burn at T-plus 6 minutes, 32 seconds, the Falcon 9’s first stage made its descent to Landing Zone 1 (LZ-1), formerly known as SLC 13 at T+8:32.

The third ground landing took place 7 minutes, 33 seconds after lifting out of LC-39A. Sonic booms, like cannon shots, rumbled across the marshlands of Merritt Island Wildlife Refuge. The landing took place at 9:47 a.m. EST (14:47 GMT).

After the first stage separated, the second stage burned for an additional seven minutes to place the CRS-10 Dragon capsule into orbit. The spacecraft separated from the booster at T-plus 10 minutes and deployed its solar arrays at T-plus 11 minutes.

Dragon, now on its own, is expected to rendezvous with the orbiting lab some two days later, on Feb. 22, for capture and berthing with the outpost.

Getting the pieces in place

SpaceX’s journey to launch from LC-39A began back in 2014 when the company signed a 20-year lease with NASA to modify the launch pad for Falcon 9 and Falcon Heavy launches (the company hopes to conduct the first flight of the FH this summer).

The first Florida launch pad SpaceX received a license agreement to use was at nearby Cape Canaveral Air Force Station’s SLC-40 in 2007. Since 2010, SpaceX has launched 26 Falcon 9 rockets from that pad (three from Vandenberg Air Force Base’s Space Launch Complex 4E and one from LC-39A).

As they did at SLC-40, SpaceX built a new horizontal integration facility (HIF) for LC-39A to assemble and prepare its launch vehicles. Additionally, a new transporter erector was constructed to carry rockets to the launch site and to position them for flight.

The HIF was built across the crawlerway originally laid out for the crawler-transporters NASA used during the Apollo and Shuttle Programs. SpaceX will use the Shuttle-era Fixed Service Structure at the top of the pad mound, though the Rotating Service Structure, which was used to place a payload into the Space Shuttle’s cargo bay, will eventually be removed and reduced to scrap.

LC-39B, which is just to the north of LC-39A, will continue to support NASA missions, particularly the super-heavy-lift Space Launch System (SLS – currently scheduled to launch next year). A “third” launch pad, 39C, has been built within the 39B perimeter to support smaller launch vehicles. It is a concrete pad that measures about 50 feet wide by 100 feet long (15 by 30 meters).

SpaceX plans to launch its commercial crew missions from LC-39A. In order to accommodate that, a lot of work still needs to be done including the addition of a crew access arm. The first demonstration launch is expected in late-2017 with a crewed demo in 2018.

While there has been some concern by the Government Accountability Office about SpaceX not making its first commercial crew launch for NASA in 2018, in a Feb. 17 press conference, SpaceX President and Chief Operating Officer Gwynne Shotwell disagreed with that assessment.

“The hell we won’t,” Shotwell said.

For today, however, that was not the focus. This mission was about ferrying cargo, crew supplies, and science experiments to the space station.

“Watching today was really different to yesterday. We were on the beach, but the atmosphere was quieter and we were watching the TV coverage on cell-phones. We were so relieved that it was a success. Actually, we were pretty speechless at first, we couldn’t really believe it had happened, but then we started clapping and slapping each other on the back,” Brigitte Schuermann, V3PO teacher, Edith-Stein School, Ravensburg, Germany, told SpaceFlight Insider.

Schuermann’s students not only got to see this historic launch, they were a part of it as their experiments were part of the payload that roared to orbit on CRS-10 thanks, in part, to CASIS.

SpaceX’s first flight from LC-39A could potentially mark the return of crewed flights from the site, which are slated to take place as soon as 2018. Photo Credit: Michael Howard / SpaceFlight Insider